Catalinbread Epoch Bias Preamp Boost Guitar Effect Pedal

The Maestro EP-3 Echoplex has been responsible for some of the most iconic tones in rock history, and we delivered a pared-down version of that preamp with the Epoch Boost. The all-new Epoch Bias expands on that circuit with a couple crucial differences. The Bias control simulates out-of-spec parts on the original, adjusting the base gain and body of the EP-3, which adds only a trivial amount of gain on its own. The new Filter control brings you the best of the early and late model EP-3, with a tasteful treble cut that lets you adapt the pedal to your rig and tone. Join us and experience the most refined version of the effect that launched a thousand discographies.

Overview

The first solid-state Echoplex that was released found its way into innumerable recording studios, guitarists found themselves plugging into it to extract its wonderful preamp qualities right before hitting the amp. And staying true to that, our original Epoch Boost was billed as something of a “mastering tool”, the finishing touch for your tone. And while you are certainly free to place it anywhere you like, almost everyone, including the pros, preferred it at the end of the chain as an “always on” to tighten up the entire mix while adding some extra sparkle on top. It just made everything sound “good.” When it came time to head back to the drawing board, we thought of a couple extra variables you could use to craft your perfect EP-3 experience. We added a Bias control which gives you a little more gain and body from the stock circuit by simulating out-of-spec parts in the preamp core, so that every pedal is “one of the good ones.” We played with the “early” and “later” circuits and found the differences to be a bit too subtle, so we decided to add a well-curated filter knob to take you from early to later and beyond, a tasteful hi-cut that lets you adapt the pedal to your rig, not the other way around. The Preamp control lets you engage a gentle filtering circuit that simulates the Volume control from the original Echoplex, acting on the tone as the echo would have. The stock EP-3 circuit adds only a trivial amount of gain by itself, so we’ve included a Boost knob to wring as much gain from it as possible, giving you a real punch where you need it. It’s certainly our most tweakable EP-3 offering to date, with everything you want and nothing you don’t.

Controls

• PREAMP: This essentially acts as the “Volume” knob from the EP-3, which is to say it’s not really a volume knob at all. That control was named such because it was the mix knob for the tape echo output, mixed with some of the “loading-down” of that echo side. At its core, it is a wet-dry mix control. But because there’s no echo here, the knob pans between “nothing” and the preamp. And when this knob is all the way down, that’s exactly what you hear: nothing. It sounds like a volume control until noon, and beyond that, it imparts some subtle frequency enhancement, on account of the loading simulation circuit. The loudest point on this knob is at about 2 o’clock.
• BOOST: Adds extra gain and volume to the circuit. When this control is set all the way down, it simulates the stock EP-3 circuit.
• BIAS: The original EP-3 pre circuit had a fixed gain and volume, dependent on one resistor value in the circuit. But because part tolerances were all over the place at the time of the EP-3’s release, there was quite a bit of variance in the overall gain in the preamp. This knob lets you dial that value in, to run the circuit hot or cold. Think of it as a gain control and a body enhancer. This control also makes light crackling noises as it is being turned, this is normal.
• FILTER: The first few hundred EP-3 units that came off the assembly line featured a slightly different preamp circuit than the rest, a little brighter than stock. And when we say “a little”, we mean it. The Filter control adds a tastefully-designed and gentle hi-cut filter that purposefully exaggerates the differences a little more than either mode, for a more refined, bluesier tone that sounds great regardless of knob position.

Power Supply

The Epoch Bias requires a 9VDC supply with 18mA of CURRENT. You can, of course, give the Epoch Bias more current than it needs. However, because of the charge pump circuit, do NOT run the Epoch Bias on anything higher than 9V. Bad things will happen, including and not limited to your warranty being voided.